title: RANTES activation of phospholipase D in Jurkat T cells: requirement of GTP-binding proteins ARF and RhoA.
abstract: The chemokine RANTES is a potent agonist of T cell activation. In an investigation of signal-transduction events activated by this chemokine, we have shown that RANTES stimulates dose-dependent phospholipase D (PLD) activity in Jurkat cells. Equilibrium-binding analyses using 125I-labeled RANTES indicated the presence of a receptor for RANTES on these cells, which has a Kd of 0.1 nM, is expressed at approximately 600 sites per cell, and a binding specificity that was not comparable with that of any of the known chemokine receptors, since 125I-labeled RANTES was displaced by macrophage-inflammatory protein-1 beta (but not macrophage-inflammatory protein-1 alpha), monocyte-chemotactic protein-1 (MCP-1), MCP-3, MCP-4, and eotaxin. RANTES-induced PLD activation was augmented by GTP gamma S, but not GDP beta S, and inhibited by the protein kinase C inhibitor bisindolylmaleimide, as well as the fungal metabolite brefeldin A, and C3 exoenzyme (Clostridium botulinum), implicating the activation of RhoA. RANTES also induced GTP-GDP exchange of immunoprecipitated RhoA. RANTES-stimulated PLD activity was dependent on an ADP-ribosylation factor(s), as assessed by inhibition studies using a synthetic inhibitory peptide of the N-terminal 16 amino acids of ADP-ribosylation factor 1. These studies indicate the potential existence of a novel receptor-mediated mechanism for activation of T cells by the chemokine RANTES.
authors.affiliation: Department of Immunobiology, DNAX Research Institute, Palo Alto, CA 94304, USA. Kbacon@neurocrine.com
authors.forename: K B
authors.initials: KB
authors.lastname: Bacon
authors.forename: T J
authors.initials: TJ
authors.lastname: Schall
authors.forename: D J
authors.initials: DJ
authors.lastname: Dairaghi
mesh_terms: D020727:ADP-Ribosylation Factors; D000595:Amino Acid Sequence; D020126:Brefeldin A; D018946:Chemokine CCL5 / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D003517:Cyclopentanes / Q000494:pharmacology; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D004852:Epoxy Compounds / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000502:physiology; D006801:Humans; D019169:Jurkat Cells; D008969:Molecular Sequence Data; D010739:Phospholipase D / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011485:Protein Binding; D011493:Protein Kinase C / Q000502:physiology; D013141:Spiro Compounds / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000201:enzymology*; D020742:rhoA GTP-Binding Protein
chemical_list: D018946:Chemokine CCL5; D003517:Cyclopentanes; D004852:Epoxy Compounds; D013141:Spiro Compounds; C089783:diepoxin sigma; D020126:Brefeldin A; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D011493:Protein Kinase C; D010739:Phospholipase D; D019204:GTP-Binding Proteins; D020727:ADP-Ribosylation Factors; D020742:rhoA GTP-Binding Protein